This invention relates to screw driving apparatus, e.g., drills, and particularly to a mechanism for attachment to a conventional drill for providing it with an automatic screw driving capability.
Screw driving apparatus including means for automatically feeding screws into the path of a screw driving bit, are known, see, for example, U.S. Pat. Nos. 4,047,611, 4,146,071, 4,404,877, 4,625,597, 5,027,679, and 5,083,483, the subject matter of which are incorporated herein by reference. Also incorporated herein are the teachings of U.S. Pat. No. 5,231,900 which issued to me. U.S. Pat. No. 5,231,900 and some of the other patents disclose, in one form or another, an elongated drill bit, means for rotating the bit about its long axis, and means for advancing and retracting the bit within an elongated sleeve. The sleeve has an opening through its wall and means are provided for sequentially inserting screws from a magazine into the sleeve through the sleeve opening and into the path of the drill bit. The bit engages the screw, advances it forwardly out of the sleeve into contact with a workpiece and drives the screw into the workpiece. The drill bit is then retracted rearwardly of the sleeve opening whereupon a new screw is injected into the sleeve for a repetition of the process.
The various patents disclose different arrangements for storing and holding the screws and for advancing them. In general, the screw advancing mechanisms tend to be complex, heavy and expensive. My patent U.S. Pat. No. 5,231,900 discloses a relatively simple screw driving mechanism, including a spring driven magazine.
The present invention includes an improvement in a screw storing and/or holding magazine, making it safer and more simple to load, and particularly to an improvement in the mechanism for advancing screws into an elongated sleeve for engagement with a drill bit.